Depth-gage



(No Model.)

A. G. HOLLISTBR.

DEPTH GAGE.

Patented Sept. 18, 1894.

Y front view of the gage.

NITED STATES PATENT OFFICE.

ALBERT G. HOLLISTER, OF HARTFORD, CONNECTICUT.

DEPTH-GAGE.

SPECIFICATION forming part of Letters Patent No. 526,105, datedSeptember 18, 1894.

" Application inea May 24, 1894. serial No. 512.283. (No model.)

To all whom it may concern:

Be it known that I, ALBERT G. HoLLisTER, a citizen of the United States,and a resident of Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements in DepthrGages, of which the following is a full, clear, and exact description,whereby any one skilled in the art can make and use the same.

The object of my invention is to provide a simple and compact devicethat shall be simple and strong in construction and one which may bemade at a price that will bring it within the reach of the averageworkman, and to this end my invention consists in the details of theseveral parts Amaking up the gage and in the combination of such partsas more particularly hereinafter described and pointed out in theclaims.

Referring to the drawings; Figure l isa Fig. 2 is a detail front view ofthe gage with the plunger case cut in vertical section to show theconstruction. Fig. 3 isa detail edge view of the device. Fig. 4 is adetail view in cross section through the plunger chamber. Fig. 5 is adetail skeleton view of the operative parts illustrating the manner ofuse. Fig. V6 is a detail view showing a modified form of connectionbetween the plunger and index lever.

The device consists mainly of a body part having a straight base and astock contain.

ing a plunger thatis adapted to be protruded through an opening in thebase the whole being compactly arranged and free from any combination ofdelicate springs and levers apt to be injured or made useless by aslight blow or fall. f

In the accompanying drawings the letter a denotes the body part of thetool as a whole which is preferably of metal cast to shape and includinga base b with a iiat straight under surface c, a stock d provided with aplunger chamber e, and the graduated arc f.

The plunger gis located in the plunger chamber and held at one end ofits path of permitted sliding movement therein by means of a spring ewhich in the form shown is a coiled spring located between the uppersurface of the plunger and a cap t' which is secured to the stock as bymeans of a clamp screws' which extends through a threaded socket in thestock and engages the cap. A gage rod k extends lengthwise through thestock passing through a hole in the cap and through a threaded hole inthe plunger, the rod being threaded to fit the threaded opening throughthe plunger. The upper end of the rod which projects beyond the cap ofthe plunger chamber is provided with a graduated surface lo marked toany scale desired and preferably on a iiattened portion of the rod.

An index lever Z is pivoted to the body part of the tool with the longerarm Z terminating in a pointer which traverses the graduated arc and bythis position indicates the position of the plunger'within the chamber,a short arm of the lever engaging the plungerso that any lengthwisemovement of the plunger causes a traversing movement 0f the outer end ofthe lever across the graduated arc.

In the preferred form of the device the arm l2 of the lever projectsinto an open socket e in the side of the plunger the wall of the chamberbeing cut away to enable the parts to be engaged as illustrated. Thisend of the lever is rounded and Iits closely between the parallel wallsof the socket so as to cause the plunger and lever to move together, butthe contact is not loose enough to allow of any lost motion betweenthe-parts. p

The central mark on the graduated scale is the Zero mark and when theplunger is lifted to a position which places the index end of the leveron the zero mark of the arc the lower end of the gage rod is located inthe plane of the surface c of the base of the implement, as shown inFig. 5 of the drawings. The method of using the instrument is asfollows: If a channel is to be planed in the surface of a piece of metalthe gage rod is screwed downward so that the lower end of the rodprojects beyond the surface of the base va distance equal to the depthof the channel or groove, when theparts are arranged witli the index endof the lever on zero of the graduated arc. The proper adj ustment of thegage rod is determined from the scale marked on the upper part of it,the upper edge of the cap being used as the index surface in connectionwith the marks on IOO the gage. When the gage rod has been protrudedthis desired distance it is clamped firmly to the plunger by means of aclamp screw m which extends through a slot inthe wall of the plungerchamber and into a threaded socket in the plunger, the bottom wall ofwhich is made thin so that by turning the clamp screw inward the plungermay be clamped firmly to the rod. The implement is then applied to thework after the channel or groove has been started and the position ofthe index arm of the lever on the are will indicate whether the groovehas been cut to a snfiicierit depth or not. It theindex end of the leveris located at the right of the zero of the gage it will show that thechannel is too deep, and if at the left of the gage it will show that itisnot of the required depth to conform to the gage as set. Owing to thedifference in length between the two arms of the lever asinall movementof the plungerl is multiplied at the index end of the lever so that therelative conditionof a surface as to depth of various parts can bedetermined with great accuracy.

A modified form of device as to the means of connecting the plunger andthe index lever is shown in Fig. t of the drawings where a segment ofagear cut on the side of the pivot end of the lever is arranged toengage the teeth of a rack cut in the side of the plunger. This is notso desirable a form of connection owing to the chance for lost motionbetween the engaged teeth. Provision may be made for expanding the shortarm of the lever so as to take up any wear or lost motion between therounded surfaces of the lever arm and the opposite surfaces of thesocket in the plunger, the parts, however, being in the first instancethoroughly hardened to reduce the wear to a minimum.

It is obvious that the device may be modified in several featureswithout departing from the invention andI do not limit myself to theprecise construction of the plunger, the gage rod, and the index leverand its connections, as in the form described.

I claim as my inventionl. In combination in a depth gage, a body part, astock having a plunger chamber, a graduated arc, and a base having astraight edge, a reciprocating plunger located within the chamber, athreaded gage rod extending through a threadedsocket in the plunger andwith its lower end adapted to project beyond the straight surface of thebase, and an index lever pivoted to the body part with a short armengaging the plunger whereby a reciprocating movement of the plunger istranslated to a circular movement of the outer end of the lever, allsubstantially as described.

2. In combination with a body part having a plunger chamber, a graduatedarc, and a straight edge, a reciprocating plunger located within thechamber,a springlocated between the plunger and an end wall of theplunger chamber, a gage rod having a threaded part fitting a threadedsocket in the plunger and with its lower end extending beyond thesurface of the base, and a graduated scale marked on the upper part ofthe rod, an index lever pivoted to the body part of the tool with theshort arm of the lever in engagement with the plunger and the longer armadapted to traverse a graduated are, all substantially as described.

3. In combination with a stock havinga [lat working face and a plungerchamber at substantially right angles thereto, a graduated are, areciprocating plunger located within the chamber, a spring locatedbetween the plunger and an end wall of the plunger cl1amber, a guage rodhaving a threaded part fitting a threaded socket in the plunger and agraduated scale marked on the upper part of the rod, a clamp screwadapted to clamp the plunger and gage rod together, an index leverpivoted to the stock and with its short arm in engagement with theplunger and its longer arm adapted to traverse the graduated arc, allsubstantially as described.

4. In combination in a depth gage, a stock having a flat working face, areciprocating plunger borne on the stock, a gage rod adj ustablyconnected to the plunger, a graduated scale on the gage rod, a graduatedaic on the body part of tho stock and an index lever pivoted to thestock and having a short arm in engagement with the plunger, the end ofthe gage rod being located in the plane IOO of the working surface whenthe index end of the lever registers with the zero of the graduated arc,all substantially as described.

5. In combination in a depth gage,a body part, a stock having a plungerchamber, a graduated arc, a brace having a straight edge, areciprocating plunger located within the chamber, a recess in the wallof the plunger, a threaded gage rod extending through a threaded socketin the plunger and with its lower end adapted to project beyond the yALBERT G. HOLLISTER.

Witnesses:

CHAS. L. BURDETT, ARTHUR B. J ENKINs.

